This invention relates generally to a baler for forming cylindrical bales of crop material, commonly referred to as a round baler. More particularly, this invention pertains to round bale net wrapping apparatus having an improved net dispensing mechanism.
Prior art balers of this type generally have a bale forming chamber defined by an apron comprising an array of side-by-side belts, transverse slats trained on chains, a plurality of rolls or a combination of these various elements, e.g., rolls and belts. Crop material, such as hay, is picked up from the ground as the baler traverses the field, fed into a flexed or adjustable chamber where it is rolled up to form a compact cylindrical bale. The formed bale is wrapped in its compacted form while still inside the bale forming chamber by net, twine or the like, prior to ejecting the bale from the chamber onto the ground for subsequent handling.
Exemplary of prior art round balers of the general type mentioned above is the baler disclosed in U.S. Pat. No. 4,956,968 issued in the name of K .R. Underhill on Sep. 18, 1990. This baler includes a mechanism for dispensing a net wrapping material into a bale forming chamber to circumferentially wrap a formed cylindrical bale. A unique net clamping arrangement is provided for inserting the net tail into the chamber when wrapping operation commences. In net wrapping systems of this type it is crucial to good bale formation for the net to be wrapped snugly around the crop material and also to be evenly spread across the full width of the bale or substantially the full width.
Problems have been encountered in attempts to accomplish the above advantages because the net being issued from the supply roll and guided through the dispensing mechanism has gone askew in the past for various reasons. The net pulling force is provided by virtue of its leading edge being fed into the nip between the bale and the apron whereby it is drawn around the bale as it is held between the moving bale and apron. When a net encounters pulling force of this nature it tends to reduce the nominal width of the flexible net whereupon a "bunch up" of the net material occurs as it is being fed into the mechanism for dispensing net around the formed bale. In this particular dispensing mechanism, comprising opposing flat clamping members through which the net is guided, it is important for the net to be maintained at its nominal width immediately up stream along its path of travel which in turn results in smooth feeding of the net downstream of the flat clamping members and thereby provide smooth effective feeding.